The MRI apparatus is an imaging diagnostic apparatus which magnetically excites nuclear spins of an object set in a static magnetic field with RF (radio frequency) signals having the Larmor frequency and reconstructs an image based on MR (magnetic resonance) signals generated due to the excitation.
As one of imaging methods for MRI apparatuses, the AFI (Asymmetric Fourier Imaging) method is known. In the AFI method, data are sampled so as to be asymmetric in the wave number direction in the k-space. Then, a phase correction is performed using a phase distribution estimated based on the sampled self data. After the phase correction, image data are reconstructed. The AFI method enables to generate image data equivalent to image data generated from data symmetrically sampled in the k-space.
For this reason, according to the AFI method, reduction of an echo time (TE) is possible when a direction in which k-space data are asymmetric is a readout direction of the k-space data. On the other hand, when a direction in which k-space data are asymmetric is an encode direction, an imaging time can be reduced. As a pulse sequence used for the AFI method, the series of an FSE (fast spin echo) sequence, such as a FASE (fast advanced spin echo or fast asymmetric spin echo) sequence, can be mentioned.